Conditions InDepth: Pneumonia

Pneumonia is a serious infection of the lungs that causes the air sacs in the lungs to fill with pus and other liquid. The infection may be caused by any of the following causative agents: bacteria, virus, fungi, and mycoplasma.
In general, pneumonia is divided into two types: community acquired or hospital or nursing home acquired.

You may get pneumonia simply because you encounter an organism that you breathe into your lungs. Whether or not you get sick depends on the contagiousness of the organism, the number of organisms you inhaled, and the ability of your immune system to fight infections.

In the United States, pneumonia is a very common illness, especially among people who are elderly.

Revision Information

This content is reviewed regularly and is updated when new and relevant evidence is made available. This information is neither intended nor implied to be a substitute for professional medical advice. Always seek the advice of your physician or other qualified health provider prior to starting any new treatment or with questions regarding a medical condition.